Mac: Introduce "StaticCast" variants of base::mac::FooCastStrict, which do not typecheck in Release

base/mac/foundation_util.h

Index: base/mac/foundation_util.h
diff --git a/base/mac/foundation_util.h b/base/mac/foundation_util.h
index ee23a17fb16e6c0c5c6856c6cd0ccbd9dd43c120..6505e614ed56b2120a23d8318126a90bc063112f 100644
--- a/base/mac/foundation_util.h
+++ b/base/mac/foundation_util.h
@@ -272,14 +272,16 @@ template<typename T>
 T CFCast(const CFTypeRef& cf_val);
 
 template<typename T>
-T CFCastStrict(const CFTypeRef& cf_val);
+T CFCastStrict(const CFTypeRef& cf_val) {
+  DCHECK(!cf_val || CFCast<T>(cf_val));
+  // Note: CFTypeRef is const void*, but CGColorRef and some others are non-
+  // const. So this may also cast away a const qualifier.
+  return (T)(cf_val);
+}
 
 #define CF_CAST_DECL(TypeCF) \
 template<> BASE_EXPORT TypeCF##Ref \
-CFCast<TypeCF##Ref>(const CFTypeRef& cf_val);\
-\
-template<> BASE_EXPORT TypeCF##Ref \
-CFCastStrict<TypeCF##Ref>(const CFTypeRef& cf_val);
+CFCast<TypeCF##Ref>(const CFTypeRef& cf_val);
 
 CF_CAST_DECL(CFArray);
 CF_CAST_DECL(CFBag);
@@ -339,9 +341,8 @@ T* ObjCCast(id objc_val) {
 
 template<typename T>
 T* ObjCCastStrict(id objc_val) {
-  T* rv = ObjCCast<T>(objc_val);
-  DCHECK(objc_val == nil || rv);
-  return rv;
+  DCHECK(!objc_val || ObjCCast<T>(objc_val));
+  return reinterpret_cast<T*>(objc_val);
 }
 
 #endif  // defined(__OBJC__)